Effective mosquito repellents can limit the transmission of vector-borne diseases to humans. Consequently, there is an urgent need to develop mosquito control strategies that prioritize eco-friendly and cost-effective repellents. Essential oils (EOs) have enormous potential for mosquito repellency. Here, cinnamon, basil, eucalyptus, and peppermint EOs were investigated for adulticide and repellency properties against Culex pipiens as well on the oviposition behavior of gravid females from laboratory (lab test) and field (field test) populations. Cinnamon oil was an effective oviposition deterrent regardless of the population and had high adulticidal activity with toxicity index of 75.00% at 24 h of exposure, relative to deltamethrin. In addition, it exhibited effective repellency at 98.01% and 71.22% at 6.67 and 1.71 µl/cm², respectively. Peppermint oil had the least adulticidal activity with toxicity index of 6.2% at 24 h, and it resulted in low repellency at 70.90% and 50.64% at 6.67 and 1.71 µl/cm², respectively. On average, basil and eucalyptus oils showed some adulticidal efficiency, repellency, and oviposition deterrent activity. For all treatments, the oviposition deterrent index values of gravid females from natural populations (field test) were lower than those from lab-reared (lab test) females. Different ratios of monoterpenoids, phenylpropanoids, and fatty acids in the EOs tested likely account for the activity variations observed. Our results suggest cinnamon, basil, eucalyptus, and peppermint EOs, which are widely available, economical, and eco-friendly, with good potential for mosquito control strategies.

Infections associated with the emergence of multidrug resistance and mosquito-borne diseases have resulted in serious crises associated with high mortality and left behind a huge socioeconomic burden. The chemical investigation of Lavandulacoronopifolia aerial parts extract using HPLC–MS/MS led to the tentative identification of 46 compounds belonging to phenolic acids, flavonoids and their glycosides, and biflavonoids. The extract displayed larvicidal activity against Culex pipiens larvae (LC₅₀ = 29.08 µg/mL at 72 h). It significantly inhibited cytochrome P-450 monooxygenase (CYP450), acetylcholinesterase (AChE), and carboxylesterase (CarE) enzymes with the comparable pattern to the control group, which could explain the mode of larvae toxification. The extract also inhibited the biofilm formation of Pseudomonas aeruginosa by 17–38% at different Minimum Inhibitory Concentrations (MICs) (0.5–0.125 mg/mL) while the activity was doubled when combined with ciprofloxacin (ratio = 1:1 v:v). In conclusion, the wild plant, L.coronopifolia, can be considered a promising natural source against resistant bacteria and infectious carriers.

Background: One of the most important problems facing the silk industry in Egypt is the existence of a good hybrid that can withstand fluctuations in climatic change, which is the main reason for silkworm susceptibility to bacterial infection. Results: This study focused on the impact of feeding the silkworm larvae from the last day of the 3rd larval instar till the 1st day of the 5th larval instar on three species of lactic acid bacteria: Lactobacillus acidophilus, Lactobacillus casei, and Lactobacillus delbrueckii. Three different concentrations (10⁶, 10⁷, and 10⁸ CFU/ml) of each species were evaluated individually as treatment during the rearing season to reduce the expectation of diseases. The results indicated that each Lactobacillus sp. has improved the immune system of the silkworm, to some extent. Accordingly, treated larvae were more resistant to pathogens, as observed in low mortality records relative to control. Scanning electron micrograph of larval foregut revealed the association of Lactobacillus sp., as solitary and colonized bacterial cells, within crypts of the crop region and their attachment to its wall by biofilaments. Histochemical analysis of the silk gland at the end of the 5th larval instar showed great enhancement in fibroin and sericin production in treated silkworms with all tested probiotics, especially Lactobacillus acidophilus compared to untreated ones. Conclusion: Overall, incorporating Lactobacillus sp. into silkworm-rearing diets represents a hopeful strategy to boost their growth, health, and productivity, also fostering sustainable practices in sericulture.